Sheet-shaped heating element and method for preparing the same

Abstract

Disclosed are a sheet-shaped heating element, which has the advantages of excellent attachability and no lateral displacement of a heat generating composition due to its load, and a method for preparing the same. The sheet-shaped heating element is characterized in that the film or sheet is formed with multiple cells having a height of 0.1-50 mm, a width of 1-100 mm and a distance oxidizable metal powder-containing between cells of 0.1-50 mm, and an oxidizable metal powder-containing heat generating composition is filled in the cells, and a pressure sensitive adhesive or a pharmacologically active material-containing adhesive matrix is attached to the bottom face of the heating element. Such flexible heating element can be attached to bendable portions of humans or animals and is not detached even after the heat generating composition is cured.

1 . A sheet-shaped heating element, comprising a multiple cell-formed film or sheet, wherein each cell is 0.1-50 mm high and 1-100 mm wide and positioned apart from adjacent cells at a distance of 0.1-50 mm, and is filled with an oxidizable metal powder-containing heat generating composition.  
     
     
         2 . The heating element as defined in  claim 1 , wherein the distance between cells is long enough to correspond to 17.4% or more of the cell height.  
     
     
         3 . The heating element as defined in  claim 1 , wherein, as the film or sheet, use is made of a single layer or multiple layers of a foamed or defoamed film, sheet, paper, non-woven, woven fabric or knitted fabric.  
     
     
         4 . The heating element as defined in  claim 1 , wherein a pressure sensitive adhesive or a pharmacologically active material-containing adhesive matrix is attached onto the bottom face of the heating element.  
     
     
         5 . A method for preparing the sheet-shaped heating element, comprising the following steps of: 
 compressing a film or sheet under heating or vacuum, or by a molder, to form the film or sheet with multiple cells, each cell having a height of 0.1-50 mm, a width of 1-100 mm and a distance between cells of 0.1-50 mm;    filling an oxidizable metal powder-containing heat generating composition in the cell, followed by sealing the cell; and    attaching a pressure sensitive adhesive or a pharmacologically active material-containing adhesive matrix onto the bottom face of the heating element.